Surgical cutting devices are generally known and used for the removal of hard and/or soft tissue, such as in the vicinity of the knee joint. Such cutting devices are used in, for example, a joint cavity, where they can be guided endoscopically by separately inserting a viewing device having a light source and an observation portion. Such operations are successfully used in organs and joints lying not too deep underneath the skin.
When operations are being carried out on organs lying deeper, other techniques are currently used. If, for example, tissue has to be removed from the uterus, prostate, or urinary bladder, such as mucous membrane or other tissues, it was customary until now to use a so-called “loop.” This is a loop-shaped cutting wire which is brought to a first potential, while the wall of the uterus is brought to a second, different potential. Tissue is removed by moving the loop along the uterus wall. In order to be able to carry out such an operation, it is necessary to dilate the uterus. Dilation is carried out by introducing a fluid. In order to maintain the effect of the potential difference, a non-conducting fluid is used, for example a 5% sorbitol solution. Because wounds are caused during the treatment described above, a good part of this fluid is resorbed into the patient's bloodstream (by way of the uterus). This can lead to highly dangerous electrolyte displacements. It has been found that the tissue can be removed more easily by working with a high-frequency monopolar electric current, but there is a risk of high-frequency electric current leading to internal and external burns. The loop is generally fitted on an endoscope and moved back and forth along the uterus wall with the endoscope. The tissue cut off during this treatment has to be removed from the uterus, which considerably extends the duration of the operation. Furthermore, the doctor has to check that all detached material actually has been removed.
This means that such operations are very time-consuming and require the surgeon to repeatedly move the device back and forth. This is tiring and consequently difficult to learn. Moreover, the patient has to be monitored continually during the operation, in order to prevent the undesirable phenomena described above. It is not uncommon for such an operation to be broken off because the patient's life is endangered by the side effects.
On the other hand, it is desirable to be able to carry out such operations instead of simply performing a hysterectomy.
WO 96/11638 discloses a cutter including a hollow stem and a cutting head accommodated inside a rigid housing. This rigid housing likewise contains a viewing channel with the necessary optics. U.S. Pat. No. 5,195,541 describes a laparoscopic discectomy apparatus. For a laparoscopic method it is essential to inflate the related cavity using gas. The gas feed is discontinuous and has no effect on viewing of the operation site.
Fluid is introduced by way of a space between the stem and the rigid housing and discharged together with the detached tissue through the hollow stem of the cutter.
This device could be satisfactory for the removal of tissues from certain body cavities, such as from the bladder. However, in the case of other body cavities, it is necessary to “blow up” the cavity before treatment can be carried out. An example of this is the uterus, in which it is important that the amount of enlargement of the organ be accurately controlled. The irregular discharge of fluid through the hollow stem of the cutter, caused partly by the irregular release of tissue, means that it cannot be guaranteed that the pressure inside the cavity is accurately controlled.
Such a device is consequently not very suitable for use in the treatment of such a cavity.